Attempting to define diet food depends very much on what's currently in fashion in weight loss. Who would have imagined ten years ago that fatty meats and dairy would be considered diet foods, yet if you follow Atkins, they certainly are!

However, if you ignore the fads, diet foods would generally be seen as those which are low in fat and sugar. While most carbs have been out of fashion lately, good sources such as fresh fruit and vegetables, and those made from whole grains, will always help anyone attempting to lose weight in a healthy, sustainable way.